This invention relates to an image processing apparatus and method and, more particularly to an image processing apparatus and method applied to an image forming apparatus which forms a color image on a print medium in accordance with, e.g., an electrophotographic method.
Conventionally, in an image forming apparatus which forms an image where one pixel is represented by 8-bit (256 levels) image data in accordance with an electrophotographic method, image formation by using a look-up table (LUT) to correct a printer characteristic to a linear characteristic is known.
However, in the above image formation, when the printer characteristic is forcibly changed into a linear characteristic by using an LUT, tonality at a highlight portion (low-density portion) of a formed image is not satisfactorily represented with respect to resolution of human eyes, due to, e.g., .gamma. characteristic unique to electrophotography. Such highlight portion with insufficient tonality may even have a pseudo outline. On the other hand, an attempt to improve the tonality representation capability by increasing the number of bits per pixel in all the image signals such as image input signal, may prolong the processing time, and increase memory capacity necessary for handling a large amount of data, thus increasing the cost of the apparatus.